10 Cosmetic Ingredients to Avoid

When it comes to makeups, lotions, soaps/shampoos, and other beauty products, the ingredients list can get confusing. What the heck is diethylhexyl phthalate anyway? In the United States, oversight of cosmetics is painfully lacking.

Luckily, we’re here to help guide you through some dangerous ingredients you should avoid when shopping for personal care products.

Here’s a quick breakdown of some of the worst offenders:

  • Formaldehyde
  • Paraformaldehyde
  • Quaternium-15
  • Parabens
  • Heavy metals
  • Phthalates
  • PABA
  • P-Phenylenediamine
  • Toluene
  • Artificial fragrances

Let’s take a look at each of these in detail and see why they’re so dangerous.



Formaldehyde is a preservative. You probably remember formaldehyde from your high school biology class. Yes, it’s the chemical they use to preserve animals for dissection. And, yes, it smells foul.

It’s hard to believe formaldehyde is an ingredient in any beauty products, but it is. It can be found in nail polish, body wash, baby shampoos, and hair products.

Many people are allergic to formaldehyde,1 and it can cause skin irritation, itching, and rashes. In addition, formaldehyde is a carcinogen.2 It can promote tumor formation when inhaled or absorbed through the skin.


Paraformaldehyde and Quaternium-15

These two chemicals are known as formaldehyde-releasing products. The name says it all: they… release… formaldehyde. And we already know how bad formaldehyde is. Several other cosmetic ingredients can release formaldehyde. These include:

  • DMDM hydantoin
  • Imidazolidinyl urea
  • Diazolidinyl urea
  • Polyoxymethylene urea
  • Sodium hydroxymethylglycinate
  • 2-bromo-2-nitropropane-1,3-diol (bromopol)
  • Glyoxal

Some of these have other known risks. For example, quaternium-15 can cause skin irritation on its own.3 In high concentrations, it can cause chemical burns. However, most cosmetics only contain small amounts of quaternium-15, so this is an unlikely side effect.

Of greater concern is an issue called sensitization. When some people are exposed to quaternium-15 over long periods of time, they can develop allergies.4 Notably, these increase the likelihood of adverse reactions to anesthetics. This risk is greatest in people who work with cosmetic products daily, such as hairdressers and nail salon workers.



Parabens are found in many household products, including:

  • Shampoos
  • Conditioners
  • Lotions
  • Body washes

Check the label! Look for any chemical that ends in paraben (e.g., methylparaben, butylparaben, etc.).

These chemicals can cause cancer and reproductive harm in addition to developmental problems for children.5


Heavy Metals

Mercury and lead! Surely, no one would put such harmful chemicals in cosmetics, right? Wrong. Despite overwhelming evidence that lead and mercury cause serious harm, many household products contain these metals.6,7

Heavy metals can be found in makeup, sunscreen, toothpaste, nail polish, and even eye drops. Yikes! Some products don’t list heavy metals in their ingredients, but they can be found as contaminants in other ingredients. To avoid heavy metals, use colored makeup products sparingly.



Phthalates have been linked to cancer and reproductive damage.8,9 They also cause developmental disorders in children.10 These chemicals have been banned in the EU, but regulations in the US aren’t as strict.

On the label, they may be listed under any of the following names:

  • Phthalate
  • DEP
  • DBP
  • DEHP
  • Fragrance

Yes, fragrance. We’ll talk about fragrance more later on. One of the big problems with “fragrance” is ambiguity. Manufacturers don’t have to list what goes into their fragrances. This can make it very hard for consumers to shop selectively. Our best advice: avoid products with “fragrance” altogether.

Other products known to have phthalates include makeup, body wash, hair products, and nail polish.



PABA is used primarily in sunscreen. It effectively protects against UVB rays, but… you guessed it: it has some serious side effects. PABA has been linked with thyroid disorders and other endocrine dysfunctions.11

PABA is rarely used anymore. However, similar chemicals have replaced it, and they can be just as harmful. Look out for the following ingredients in your sunscreen:

  • PABA
  • Padimate O
  • 4-aminobenzoic acid
  • Para-aminobenzoic acid
  • P-aminobenzoic acid
  • Et-PABA
  • 2-ethylhexyl ester
  • P-carboxyaniline



P-Phenylenediamine is an oxidizer found in hair dye. P-Phenylenediamine is a carcinogen and can also cause skin irritation.12,13 If ingested, p-phenylenediamine can damage the kidneys.14 It can even be fatal.

The best way to avoid p-phenylenediamine is to forgo dying your hair. Hairdressers should use caution when applying dye to clients’ hair. They should always use gloves and may consider facial protection as well.



Toluene is an oil, and it is a component of crude oil. It is a gasoline additive.

Exposure can cause developmental disorders in children. In adults, toluene can damage internal organs and reproductive health when inhaled.15

Toluene is found in nail polish and hair dyes.



Just what is “fragrance?” Well, no one really knows…except for the manufacturer whatever scented lotion or perfume you’re looking at. And they aren’t telling us! There are as many as 3,000 different ingredients that could possibly go into “fragrance” and, as it turns out, what you don’t know can hurt you.

As we discussed earlier, fragrance sometimes contains phthalates as well as formaldehyde and other toxic ingredients.16  Yikes!  These ingredients range from skin irritants to carcinogens and pretty much every risk mentioned with other cosmetic ingredients so far.

Our advice: find a lotion, deodorant, body wash, or perfume that doesn’t use “fragrance.”


More Information on Toxic Ingredients in Cosmetic Products

There are many reputable organizations that provide information to consumers about cosmetic products.

The Campaign for Safe Cosmetics is a great resource. They provide lists of dangerous ingredients and known risks for using these products. They are actively lobbying for more transparency and additional regulations in the cosmetics industry.



  1. Pontén A, Bruze M. Formaldehyde. Dermatitis. 2015;26(1), 3-6. DOI: 10.1097/DER.0000000000000075.
  2. American Cancer Society. https://www.cancer.org/cancer/cancer-causes/formaldehyde.html. Accessed 7/22/2020.
  3. Quaternium-15 (Formaldehyde-Releaser). EWG’s Skin Deep. https://www.ewg.org/skindeep/ingredients/705478-QUATERNIUM-15. Accessed 7/22/2020.
  4. Dong S, Acouetey DS, Guéant-Rodriguez RM. Prevalence of IgE against neuromuscular blocking agents in hairdressers and bakers. Clin Exp Allergy. 2013;43(11):1256-1262. DOI: 10.1111/cea.12189.
  5. Darbre PD, Harvey PW. Paraben esters: review of recent studies of endocrine toxicity, absorption, esterase and human exposure, and discussion of potential human health risks. J Appl Toxicol. 2008;28(5):561-578. DOI: 10.1002/jat.1358.
  6. Rosen JF. Adverse health effects of lead at low exposure levels: trends in the management of childhood lead poisoning. 1995;97(1-3):11-17. DOI: 10.1016/0300-483x(94)02963-u.
  7. Bernhoft RA. Mercury toxicity and treatment: a review of the literature. J Environ Public Health. 2012;2012:460508. DOI: 10.1155/2012/460508.
  8. Substances Listed in the Fourteenth Report on Carcinogens. National Toxicology Program. https://ntp.niehs.nih.gov/ntp/roc/content/listed_substances_508.pdf. Accessed 7/22/20.
  9. Jurewicz J, Hanke W. Exposure to phthalates: reproductive outcome and children health. A review of epidemiological studies. Int J Occup Med Environ Health. 2011;24(2):115-141. DOI: 10.2478/s13382-011-0022-2.
  10. Swan SH, Main KM, Liu F, et al. Decrease in anogenital distance among male infants with prenatal phthalate exposure. Environ Health Perspect. 2005;113(8):1056-1061. DOI: 10.1289/ehp.8100.
  11. Krause M, Klit A, Blomberg Jensen M, et al. Sunscreens: are they beneficial for health? An overview of endocrine disrupting properties of UV-filters. Int J Androl. 2012;35(3):424-436. DOI: 10.1111/j.1365-2605.2012.01280.x.
  12. Bolt HM, Golka K. The debate on carcinogenicity of permanent hair dyes: new insights. Crit Rev Toxicol. 2007;37(6):521-536. DOI: 10.1080/10408440701385671.
  13. Schnuch A, Geier J, Uter W. National rates and regional differences in sensitization to allergens of the standard series. Population-adjusted frequencies of sensitization (PAFS) in 40,000 patients from a multicenter study (IVDK). Contact Dermatitis. 1997;37(5):200-209. DOI: 10.1111/j.1600-0536.1997.tb02435.x.
  14. Anuradha S, Arora S, Mehrotra S, Arora A, Kar P. Acute renal failure following para-phenylenediamine (PPD) poisoning: a case report and review. Ren Fail. 2004;26(3):329-332. DOI: 10.1081/jdi-200026722.
  15. Toxicological Profile for Toluene. Agency for Toxic Substances and Disease Registry. https://www.atsdr.cdc.gov/toxprofiles/tp56.pdf. Accessed 7/22/20.
  16. Campaign for Safe Cosmetics. http://www.safecosmetics.org/get-the-facts/chemicals-of-concern/fragrance/#_edn1. Accessed 7/22/20.

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